During a phone call with Finnish President Sauli Niinistö, Vladimir Putin warned it would be a “mistake” for Finland to join NATO. The call between the world leaders came with Finland expected to imminently renounce neutrality by declaring a desire to join the Western alliance. The BBC reports that Putin cited Ukraine’s desire to likewise join as a catalyst for the Russian invasion. According to the Kremlin, Putin said during the call that the “end of the traditional policy of military neutrality would be a mistake since there is no threat to Finland’s security.” During the discussion, which was reportedly straight-forward without escalating aggression, Niinistö, however, told Putin that the war in Ukraine has “altered the security environment of Finland.” Finland shares a 1,340 kilometer long border with Russia to the east; to the west, the country borders Sweden, which has likewise declared intentions to join NATO.